Chapter 19 Population in Ecosytems Flashcards
Definition of community
All the different species that live in one area and interact with one another
Definition of ecology
The study of inter relationship’s between organisms and their environment
What are biotic and abiotic factors? + eg
Biotic - living features of an ecosystem e.g. predators disease
Abiotic - non living features of an ecosystem e.g light and temperature
Definition of ecosystem
All the organisms found in one area, combined with non living aspects of their environment.
Definition of habitat
The place where an organism lives
Definition of a niche
The role of a species within its habitat, consisting of both its biotic and abiotic interactions.
Definition of Carrying capacity
The maximum size of population an ecosystem can support
Abiotic factors that affect population growth
- Temperature
- Light
- pH
- Water
Definition of intraspecific
Competition between organisms of the same species
Definition of interspecific
Competition between organisms of different species
Resources organisms may compete for?
- food
- water
-shelter - minerals
- light
- mates
Pattern of typical predator prey relationshp
- Prey is eaten by predator resulting in prey population decreasing and predator population increasing
- Fewer prey means more competition so predator population decreases
-Fewer Predator means more prey live so cycle goes again
Use of Quadrats
- For non motile organisms and can be placed along transect belt or grid coordinates
How is mark- release - capture technique used for estimating population size?
- A sample of species is caught and then marked and released in same area they were caught
- After a while another sample is taken in same area and the number of marked organisms is counted
Equation for Mark-release-capture technique
total no of individuals in first sample x no individual in second sample / number of marked individuals recaptures
Why are ecosystems describes as Dynamic?
- Population constantly rise and fall
-Any small change can have a large effect - Biotic and abiotic factors may alter the ecosystem
Definition of Primary succesion
Where an area previously devoid of life is colonised
Process of primary succession
- pioneer ( Original) species can survive harsh conditions and colonise the area
- Change abiotic factors of their environment
- Overtime allows more complex organisms to survive
Climax community
Final stage of succesion where ecosytem is stable and balanced. Reached when soil is rich enough to support large trees or shrubs and environment is no longer changing
Conservation
The protection and management of species and habitats, in order to maintain biodiversity.
Predation
The biotic condition that drives adaptations to avoid being eaten by predators.
